Intermittent Fasting: Not Just for Weight Loss?

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If you are like many people I know, after Thanksgiving you feel terrible about the food choices you made and think you have totally blown your “diet." Some will decide to take matters into their own hands immediately and get back on track. Others may start the spiral downward till New Years and let all their hard work for the year be sabotaged. And then there are those who may have heard about new research on intermittent fasting and think that's the way to undo the holiday damage.

In an unpublished study of 26 obese adults, those who fasted completely every other day and ate with no restrictions the rest of the time lost about the same amount of weight in two months as those who didn't fast at all. But four months later, after patients were off the intervention, those who had the initial "intermittent fasting" intervention had dropped more pounds and had greater improvements in memory than those on a standard diet. [Tweet this.]

Study author William Troy Donahoo, Ph.D., said at a conference that the difference in weight loss may have been due to people continuing to fast after the study ended, or that fasting somehow changes your metabolism.

So should we all jump on this bandwagon? Not so fast. This study was not peer-reviewed, which from a scientific standpoint is very important. Also it seems the participants where only actually followed for two months and then had a check-in at six months. I am very curious as to what happened in those four months that they were technically off the intervention. Instead of fasting during that time as Donahoo thinks, they may have simply been eating fewer calories then they did at the beginning of the study. Or maybe those on the standard diet simply ate more; there are too many questions to know for sure.

In an earlier paper, co-author Mark Mattson, Ph.D., wrote that intermittent fasting is consistent with the way humans evolved to eat. "From an evolutionary perspective, intermittent fasting is normal, and eating three meals a day plus snacks is abnormal. Going without food for most of the day or even for several days is a challenge that we are very capable of meeting," he stated.

Really? I'm not sure who he is was speaking of. None of my patients are capable of going without food for most of the day, nor am I—and I wouldn't want to. Plus intermittent fasting isn't realistic and doesn't teach anyone how to eat healthy in a sustainable manner.